| BeauPlan Co. | Osaka |
| Beauty and Create Co., Ltd | Tokyo |
| beBit, Inc. | Tokyo |
| Begi.net, Inc. | |
| Being Co., Ltd | Mie |
| Bekkoame//Internet | Tokyo |
| Bell Data, Inc. | |
| Bell Software, Inc. | Tokyo |
| Bell-Park Co., Ltd | Tokyo |
| BenQ Japan Co., Ltd | Tokyo |
| Beppu Mzobe Gakuen College | |
| Beppu University | |
| BeRiver Electronics, Inc. | |
| Best Kendi Co., Ltd | Tokyo |
| BestAbility Co., Ltd | Tokyo |
| BetaMind, Inc. | |
| Bewith Enterprise Ltd | Tokyo |
| Beyond Next Ventures Co., Ltd | Tokyo |
| bgrass, Inc. | |
| Big Bang System Corporation | Tokyo |
| Big Country Co., Ltd | Tokyo |
| BiG-NET | Tokyo |
| Biglobe, Inc. | Tokyo |
| Bigvan, Inc. | Tokyo |
| BIKEN Co., Ltd | |
| Billing System Corporation | Tokyo |
| Bio Academia Co., Ltd | Osaka |
| BioComo | |
| Biocomo Co., Ltd | Mie |
| Biodata Bank, Inc. | |
| BioRuby | Tokyo |
| Bios Co., Ltd | Tokyo |
| BIOSYS Corporation | Tokyo |
| Bioworks Co., Ltd | Kyoto |
| Birdman, Inc. | |
| Bis-StuDio | Tokyo |
| bitA Co., Ltd | Tokyo |
| bitBiome Co., Ltd | Tokyo |
| Bitcross Co., Ltd | Tokyo |
| bitFlyer, Inc. | |
| Bitforest Co., Ltd | Tokyo |
| Bitkey Co., Ltd | Tokyo |
| Bitscope Co., Ltd | Tokyo |
| BitSquare, Inc. | Tokyo |
| BitStar Co., Ltd | Tokyo |
| Biwako-Gakuin University | |
| BizReach Co., Ltd | Tokyo |
| BlackCrow Capital | |
| Blastmail | Tokyo |
| Blau, Inc. | Tokyo |